Method of making striated paperbpoard



June 23, 1964 H. M. GREENHousE ETAL 3,133,518

METHOD OF MAKING STRIATED PAPERBOARD 3 Sheets-Sheet 1 Filed July l5. 1961 u 15M m m1 I I d mh NN .m A ww, @N .wm ww ww wm wm ww om o QW@ u V1 w :Il: mm V ,11K 1, W ,r ,rx wf mgm m, mv of mw OMQNC O( OWCQWUC@ QOWUO mw Nm. w am OW QW QW ON vm, m Il O O O O 9 i TTOPA/EYS June 23, 1964 H. M. GREENHOUSE ETAL 3,138,513

METHOD OF MAKING STRIATED PPERBOARD 3 Sheets-Sheet 2 Filed July 13, 1961 June 23, 1964 H. M. GREENHousE ETAL 3,138,518

METHOD OF MAKING STRIATED PAPERBOARD Filed July 13, 1961 3 Sheets-Sheet 3 INVENTOR. F 4 #EA/PY M. Gesa/House -1- E HE7-Hu@ \7 D//w/CK F/QH/vc/s M. MYERS HTTOQNEYS United States Patent O METHOD F MAKING STRIATED PAPERBARD Henry M. Greenhouse, Hudson, Arthur J. Dimick, Ghent,

and Francis M. Myers, Valatie, N.Y., assignors to Columbia Box Board Mills, Inc., Chatham, NY., a

corporation of New York Filed .Iuiy 13, 1961, Ser. No. 123,870 3 Claims. (Cl. 162-109) Our invention relates to a method of making striated paperboard and more particularly to an improved method of making patterned paperboard and to the board produced by our process.

There are known in the prior art methods of making paperboard or box board which is intended for use in the manufacture of paper boxes and containers. In the methods of the prior art a plurality of successive layers of bers are built up on a moving felt. When a number of layers corresponding to the thickness of the finished board have been built up on the felt, the wet board is passed through driers and the necessary finishing operations are performed on the board. The finished board in processes of the prior art has an appearance which is determined by the nature of the stock employed and by the finishing operations performed on the stock. Most generally, it is all of a fiat color which is not particularly pleasing to the eye,

Where paperboard is to be used to make cartons or packages for goods to be merchandised, it is desirable that it be given an appearance which is pleasing tot the eye. This is accomplished in the prior art by the various operations performed on the board after it is finished. For example, the nished board may be printed with suitable colors. Alternatively, a printed decorative paper can be pasted over the`finished board. Colors can be applied to the board by spraying or the like performed on the finished board. While these methods of the prior art result in the desired decorative board, they all require operations to be performed subsequent to the board forining operation itself. Thus these methods of the prior art are time consuming and expensive. They require additional apparatus over that which is required for the board making operation.

We have invented a method of making striated paperboard which overcomes the defects of methods of decorating paperboard known in the prior art. Our method proudces decorative board as a direct result of the board manufacturing operation itself. It does not require the performance of any steps subsequent to the board forming operation. It is less time consuming and less expensive than are methods of the prior art. Our method does not necessitate the use of any additional equipment over that required for the normal paperboard making operation. Our method permits the manufacture of decorative board on existing cylinder board making machines without modification thereof.

One object of our invention is to provide a method of making striated paperboard which overcomes defects in methods of the prior art in making paperboard.

Another' object of our invention is to provide a method of making striated paperboard which is more expeditious and which is less expensive than are methods of the prior art.

A further object of our invention is to provide a method of making striated paperboard which is performed in the course of manufacture of the paperboard.

Still another object of our invention is to provide a method of making striated paperboard which does not require the use of auxiliary equipment for applying decorations to the board. Y

Patented June 23, 1964 ICC method of making striated paperboard on a cylinder board making machine without modification thereof.

Other and further objects of our invention will appear from the following description.

In general, our invention contemplates the provision of a method for making striated paperboard in which We control the process conditions in the last fiber-applying cylinder mold to cause fibers from the last vat to be deposited on the layer of fibers carried on the felt in a predetermined pattern. If desired, the fibers in the vat of the last fiber-applying mold may be made of a different color or type than those employed in the other vats of the machine to provide a desired constrast.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIGURE 1 is a schematic view of the wet end of a cylinder paperboard making machine.

FIGURE 2 is a schematic view of the water circulating system associated with the last vat of the machnie shown in FIGURE 1.

FIGURE 3 is a sectional view of the last cylinder of the paperboard making machine shown in FIGURE 1.

FIGURE 4 is a sectional view of the cylinder shown in FIGURE 3.

FIGURE 5 is a fragmentary plan view of a portion of the striated board produced by our method.

Referring now to FIGURE l of the drawings, one type of cylinder paperboard making machine on which our method can be practiced includes a top felt 10 and a bottom felt 12 on which the layers of fibrous material are deposited in a manner known to the art. As is known in the art the upper felt 10 is supported on a plurality of supporting and guiding rolls 14 and it has associated therewith a felt stretcher 16 as well as one or more whippers 18 and associated sprays. The bottom felt 12 likewise is supported with supporting and guiding rolls 20 as Well as a felt stetcher 22 and one or more whippers 24. The bottom felt passes through a plurality of vat sections indicated generally by the reference character 26. A suitable suspension of fibrous material in water is supplied to the vats 26 from the machine stuff chests (not shown) through a suitable distributing box (not shown).

In the course of passing through one of the vat secr tions 26, the bottom felt is pressed down on top of the cylinder 28 ofthe vat by means of a rubber-covered pressure roll 30. As will be described in detail hereinafter, as the felt passes over the cylinder 28 it has deposited on the underside thereof a layer of fibrous material which is carried along by the felt through the remaining cylini sure roll 34 and the suction drum 32 so that the build up Yet another object of our invention is to provide a of fibers picked up on the lower felt 12 as it passes through the cylinder section of the machine is carried by the felts to pairs of squeeze and press rolls 36 and 38 which serve to squeeze some of the water out of the fibrous layer. After leaving the groups of rolls 36 and 38, the wet board passes between a suction roll 40 and a drum 42 and thence out of the wet end of the machine to the drier. Since the structure thus far described is well known in the art, it will not be described in detail. The entire structure so far described is driven as a single unit as by applying power to the lower first press roll 38 and as required to auxiliary helper driver arrangements which may be applied to other press molds and sometimes to the cylinder molds. Y

As is pointed out hereinabove, in our method we cause the fibers deposited on the felt 12 by the last fiber-applying cylinder section 26 of the machine to be disposed in a particular pattern. It is to be understood that we control conditions in the last section 26 which applies fibers. The last fiber-depositing section can, of course, be any cylinder after the first.

Referring now to FIGURE 2, we have shown the water system of this last liber-applying unit of the machine as including a vat 44 of the counterflow type. The furnish or suspension of fibers in water is supplied to this vat through an inlet pipe 46. Stock to the system is provided by a head box 48 to which material from the stuff chest 51 is fed by an inlet pipe 50. Stock from the Jordan (not shown) feeds into the stuff chest 49 and is pumped to the head box 48 by the stock pump 51. In order to regulate the consistency of the stock fed to the box 48, a sample of the stock from the chest is fed through a valve 53 to a consistency regulator 55. This regulator 55 may be of any suitable type known to the art. For example, it may be the well-known Trimbey regulator which controls a dilution water inlet valve 57 through a linkage 59 to dilute the stock from the chest as required to maintain the desired consistency of stock fed to box 48. The overflow dam 52 inside the head box 48 serves to regulate the head of stock in the box, the overflow passing out through an outlet pipe 54. In the form of head box 48 we have shown in FIGURE 2, the construction has been greatly simplified since in the practice of our method we are concerned only with the stock which is fed to the last cylinder vat of the machine.

From the box 48 stock passes to a distributing channel 56 leading to an inlet pipe 58. Flow from the box is controlled by a regulating gate 60 the position of which is controlled by a hand Wheel 62 which causes the gate to be raised or lowered to control the ow of the stock. A pointer 64 cooperating with a scale 66 may be used to indicate the position of the gate and thus the amount of stock being fed to the channel 56. From pipe 58 the stock feeds into a screen dilution line 66 and into the screen 68 of the machine. The material discharges from the screen 68 through a pipe 70 to the mix box 72 associated with the last cylinder of the machine. Stock from the mix box fiows through pipes 74 and 76 to the inlet pipe 46 of the last vat 44 of the machine. As will be explained hereinafter, white water from the vat 44 flows out through a pipe 78 and through the vat pump 80 to a pipe 82. A screen valve 84 is adapted to be actuated to control the flow of white water back to the screen 68 to dilute the stock being fed into the unit through pipe 58. A second valve or mix box valve 86 regulates the amount of White water being fed back into the mix box 72.

Referring now to FIGURES 3 and 4, stock being fed into the vat 44 through pipe 46 is screened off from the making portion by two weirs 88 and 90. A bathe 92 disposed between the weirs permits stock to iiow under the baie and into the area surrounding the cylinder indicated generally by the reference character 94 of the machine. This arrangement rectifies some of the irregularity of flow caused by the right angle turn into the vat approach piping. From the structure just described, it will be seen that the cylinder 94 is immersed in the suspension of stock to a predetermined level.

Each cylinder of the machine includes a core 96 carrying a plurality of spiders 98 to which there are secured a plurality of parallel rods 100 having a predetermined spaced relationship. A winding wire 102 is wound around the outside of the parallel rods 100. The winding wire 102 carries a backing wire and a face Wire both of which we have indicated by the reference character 104 in the drawings. In a particular embodiment of the cylinder mold 94, the cylinder may have a 36" diameter with f/s cross rods, 0.092" diameter winding wire, a 14 mesh backing wire and a 40 mesh face wire. It is to be understood that while we have shown a cylinder of the counteriiow 11 type of our method, we could as well employ a unifiow type vat.

In operation of the vat, as the bottom felt is driven it causes the cylinder 94 to rotate. The fibrous suspension from the inlet pipe 46 fiows around the cylinder in the direction indicated by the arrows in FIGURE 3 and the cylinder itself rotates in the direction of the arrow adjacent the core in the cylinder 96. Water from the suspension flows through the face and backing wire 104 into the interior of the cylinder and out to the end of the cylinder. One wall 106 of the vat 44 is provided with a chiLnegring 108 which cooperates with a second chime ring 110 on the cylinder itself. Ring 108 carries a garter strap 109 of a type known in the art made of felt which prevents the flow of fibers into the white water area 110 in the side 106 of the vat. An adjustable spill darn 112 is positioned at each of the vat to control the level of water within the cylinder. While we have shown the individually adjustable spill dams 112 it is to be understood that in practice means is provided for adjusting the dams in unison. We provide the other side of the vat with a similar arrrangement.

From the structure so far described it will be seen that a plurality of layers of fibers are built up on the under side of the bottom felt 12 as it passes through the units 26. We so control the process conditions of the last fiber-applying unit of the machine as to cause fibers to be deposited in a predetermined pattern. We have discovered that the vat consistency, freeness and the mold head or difference in level of water inside and outside the cylinder 94 of the last vat can be regulated within limits to cause fibers from the suspension in the last cylinder to be deposited on the cylinder and thus on the felt 12 in a predetermined manner. Process conditions for any cylinder unit after the first can be controlled to produce our novel result so long as the controlled unit acts as the last fiber ply application.

In preparing the stock, we may use any natural or synthetic fibers. Suitable wood fibers may be obtained by any of the kraft, sulfite, groundwood, soda, semichemical, chemigroundwood, or other known processes. Viscose, vinyon, or glass synthetic fibers may be employed.

As is known in the art, the degree to which incoming stock can be diluted depends upon the amount of Water drained through the mold. This drainage in turn depends upon the area of the drainage surface, the mold head, the temperature and dranage characteristics or freeness of stock, and the weight of the individual ply being formed in a particular mold section. As is pointed out thereinabove, we have discovered that when we control the vat consistency, the freeness and the mold head in the last cylinder unit 44 of the machine within certain limits, fibers are deposited by the last cylinder in a pattern on the fiber sheet carried by the lower felt 12.

The first factor which we control in our process of mak ing striated paperboard is the vat consistency or consistency of stock in the last vat 44 of the machine. We have discovered that if our novel result of a patterned deposit of fibers is to be produced in the last cylinder of the machine, the vat consistency or percentage by weight of fibers in water of the stock in the last cylinder 44 must be between the limits of 0.10% and 0.25%. Outside these limits either insufiicient fibers to produce any pattern are picked up or so many fibers are picked up that a solid sheet results and no pattern appears. This vat consistency can readily be controlled by the consistency regulator 55 which regulates the consistency of the incoming stock. The vat consistency may also be controlled by recirculation.

Considering next the drainage characteristics or freeness of the stock, it is recognized that the drainage characteristics of different stocks vary widely. As is also known, the more a given type of fibers has been beaten or refined, the less freely will water drain through a mat of fibers. It is clear further that the amount of drainage water through the cylinder mold is greater for the free stock than for slow stock. Various tests all of which are empirical are used to measure the freeness of the stock. One such test is described in the Technical Bulletin T 227 m-50 Freeness of Pulp, published by the Technical Association of the Pulp and Paper Industry, 360 Lexington Avenue, New York, New York. By use of the test set forth in the publication, a freeness measure can be determined. In our process, we have discovered that for the range of vat consistencies outlined above we must use a stock having a Canadian Standard Freeness of between 200 cc. and 490 cc. as determined by the test set forth in the above bulletin. It will readily be appre- .ciated by those skilled in the art that stock of an aquivalent freeness as determined by other tests could be employed.

A third factor which we control in our process is the mold head or difference in level of the stock in the vat 44 and of the water within the cylinder 2S of the last unit 44. The essential requirement of the hydrostatic head is that it be kept constant during the process. The actual hydrostatic head which is employed depends upon vat consistency and freeness of the stock. Having a given freeness and vat consistency the head must be kept constant or the pattern of fibers may disappear completely. This factor of our process is controlled by positioning the spill gates 112 of the last unit at a height which determines the difference in level of stock outsin.c the cylinder and of white water within the cylinder. For the limits of vat consistency and freeness given above, we have discovered that the mold head must be between 11/2 inches and 31/2 inches in order that the last layer of fibers be deposited on the moving sheet in a pattern.

From the foregoing, it will be seen that the features of our process which must be maintained are a vat consistency of between 0.10% and 0.25%, a Canadian Standard Freeness of between 200 cc. and 490 cc. and a constant hydrostatic had within the range of 11/2 inches to 31/2 inches. These limits of our process are critical. If an attempt is made to practice the process outside these limits, either no satisfactory deposit of fibers in any pattern will be formed or a substantially solid sheet of fibers will be deposited on the layer carried by the moving felt.

Referring to FIGURE 5, We have shown a fragment 114 of the board produced by our process in which there are deposited on the moving board in the last unit of the machine transversely extending spaced deposits 116 of fibers. Such a pattern was produced during one trial run of the process with a vat consistency of 0.21%, a freeness of 480 cc. and a constant hydrostatic head of 3 inches.

With conditions in the last cylinder unit controlled within the limits pointed out above, fibers are deposited by the last unit of the machine in a predetermined pattern. If desired, a dye may be added to the stock fed to the last unit. Any suitable dyestuffs such as acid, basic, direct and pigment dyestuffs may be employed. Preferably, the colors employed are such as will contrast with the color of the layer of fibers on which the patterned deposit of bers are laid by the last cylinder of the machine.

In the practice of our process, deposits of layers of fibers are picked up by the moving felt 12 in the usual manner at its moves through the vats 26 up to the last vat. At the last vat, we control the vat consistency,

freeness and hydrostatic head within the limits outlined above. Under these conditions iibers are deposited in a pattern such as that shown in FIGURE 5. These bers may be colored or they may be of a dierent characteristic as those used in the other sections of the machine to produce the desired patterned paperboard.

It will be seen that we have accomplished the objects of our invention. We have provided a method of making patterned paperboard which overcomes the defects of paperboard decorating methods known in the prior art. We produce a decorative board as a direct result of the board manufacturing operations. Our method does not require the performance of any steps subsequent to the board forming operation. It is less time consuming and less expensive than are methods of the prior art. Our method does not require additional equipment over that used in the normal paperboard making operation, but permits decorative board to be made on existing cylinder machines without moditication thereof.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims Without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described. Having thus described our invention, what we claim 1. In a method of making patterned paperboard on a cylinder machine having a last liber-applying cylinder vat, the steps of controlling the vat consistency of stock in the last vat to between 0.10% and 0.25% by weight of fibers in water, controlling the freeness of stock to a Canadian Standard Freeness of between 200 cc. and 490 cc. and controlling the hydrostatic mold head to provide a head of between 11/2 inches and 31/2 inches in said last cylinder vat.

2. In a method of making patterned paperboard on a cylinder machine having a last cylinder vat, the steps of controlling the vat consistency of stock in the last vat to between 0.10% and 0.25% by weight of fibers in water, controlling the freeness of stock to provide a Canadian Standard Freeeness of between 200 cc. and 490 cc. controlling the hydrostatic mold head to provide hydrostatic mold head of between 11/2 inches and 31/2 inches in said last cylinder vat and adding a dye to the stock fed to said last cylinder vat.

3. In a method of making patterned paperboard on a cylinder machine having a last cylinder vat, the steps of controlling the vat consistency of stock in the last vat to about 0.21% by Weight of fibers in water, controlling the Canadian Standard Freeness of stock to about 480 cc. and controlling the hydrostatic mold head to a constant head of about 3 inches in said last cylinder vat.

References Cited in the tile of this patent UNITED STATES PATENTS 670,847 Cornell Mar. 26, 1901 1,180,149 Hercher Apr. 18, 1916 1,471,170 Kaye Oct. 16, 1923 2,083,818 Berry June 15, 1937 2,402,966 Linzell July 2, 1946 FOREIGN PATENTS 767,282 France May l, 1934 

1. IN A METHOD OF FMAKING PATTERENED PAPERBOARD ON A CYLINDER MACHINE HAVING A LAST FIBER-APPLYING CYLINDER VAT, THE STEPS OF CONTROLLING THE VAT CONSISTENCY OF STOCK IN THE LAST VAT TO BETWEEN 0.10% AND 0.25% BY WEIGHT OF FIBERS IN WATER, CONTROLLING THE FREENESS OF STOCK TO A CANADIAN STANDARD FREENESS OF BETWEEN 200 CC. AND 490 CC. AND CONTROLLING THE HYDROSTATIC MOLD HEAD TO PROVIDE A HEAD OF BETWEEN 1 1/2 INCHES AND 3 1/2 INCHES IN SAID LAST CYLINDER VAT. 